Consolidated Statements of Shareholders' Equity (USD $) In Thousands	Total	Common Shares [Member]	Preferred shares	Additional Paid-in Capital [Member]	Accumulated other comprehensive (loss) income	Currency translation adjustment	Unfunded pension obligation	Unrealized gain on investments	Retained earnings	Common shares held in treasury	Noncontrolling interests
Balance at beginning of year at Dec. 31, 2011		$ 84,767	$ 35,750	$ 3,803,796	$ (12,644)	$ 4,267	$ (23,076)	$ 6,165	$ 4,035,103	$ (1,479,230)
Issuance of common shares		693		58,048
Issuance of preferred shares			0	0
Redemption of preferred shares			0	0
Change in currency translation adjustment	28,488					28,488
Change in unfunded pension obligation, net of tax	(4,294)						(4,294)
Change in unrealized losses on investments, net of tax	(953)							(953)
Net income	1,134,514								1,134,514
Net income attributable to noncontrolling interests	0								0
Dividends on common shares									(155,993)
Dividends on preferred shares	(61,622)								(61,622)
Loss on redemption of preferred shares	0								0
Repurchase of common shares	(532,927)									(532,927)
Noncontrolling interests											0
Total shareholders' equity	6,933,496
Balance at end of year at Dec. 31, 2012	6,933,496	85,460	35,750	3,861,844	10,597	32,755	(27,370)	5,212	4,952,002	(2,012,157)
Issuance of common shares		1,197		77,783
Issuance of preferred shares			10,000	231,265
Redemption of preferred shares			(11,600)	(269,265)
Change in currency translation adjustment	(31,778)					(31,778)
Change in unfunded pension obligation, net of tax	9,861						9,861
Change in unrealized losses on investments, net of tax	(918)							(918)
Net income	673,442								673,442
Net income attributable to noncontrolling interests	(9,434)								(9,434)
Dividends on common shares									(142,217)
Dividends on preferred shares	(57,861)								(57,861)
Loss on redemption of preferred shares	(9,135)								(9,135)
Repurchase of common shares	(695,304)									(695,304)
Noncontrolling interests	56,627										56,627
Total shareholders' equity	6,766,159
Balance at end of year at Dec. 31, 2013	6,709,532	86,657	34,150	3,901,627	(12,238)	977	(17,509)	4,294	5,406,797	(2,707,461)
Balance at beginning of year at Sep. 30, 2013
Net income	276,000
Net income attributable to noncontrolling interests	(4,000)
Dividends on preferred shares	(14,000)
Loss on redemption of preferred shares	0
Noncontrolling interests	56,627										56,627
Total shareholders' equity	6,766,159
Balance at end of year at Dec. 31, 2013	6,709,532	86,657	34,150	3,901,627	(12,238)	977	(17,509)	4,294	5,406,797	(2,707,461)
Issuance of common shares		580		48,038
Issuance of preferred shares			0	0
Redemption of preferred shares			0	0
Change in currency translation adjustment	(8,892)					(8,892)
Change in unfunded pension obligation, net of tax	(12,067)						(12,067)
Change in unrealized losses on investments, net of tax	(886)							(886)
Net income	1,068,113								1,068,113
Net income attributable to noncontrolling interests	(13,139)								(13,139)
Dividends on common shares									(134,225)
Dividends on preferred shares	(56,735)								(56,735)
Loss on redemption of preferred shares	0								0
Repurchase of common shares	(551,409)									(551,409)
Noncontrolling interests	55,501										55,501
Total shareholders' equity	7,104,411
Balance at end of year at Dec. 31, 2014	7,048,910	87,237	34,150	3,949,665	(34,083)	(7,915)	(29,576)	3,408	6,270,811	(3,258,870)
Balance at beginning of year at Sep. 30, 2014
Net income	280,000
Net income attributable to noncontrolling interests	(3,000)
Dividends on preferred shares	(14,000)
Loss on redemption of preferred shares	0
Noncontrolling interests	55,501										55,501
Total shareholders' equity	7,104,411
Balance at end of year at Dec. 31, 2014	$ 7,048,910				$ (34,083)